Labour's elder statesman Jack Straw is to stand down as an MP at the next general election, he announced today.
The former home secretary, foreign secretary and lord chancellor broke the news to his constituency Labour Party in Blackburn, the Lancashire town which he has served as MP since 1979.
Mr Straw, 67, said that it would be a "terrible wrench" to leave the House of Commons at the election, scheduled for May 2015, but said he did not want to "push my luck" by attempting to stay on into his 70s.
Labour leader Ed Miliband paid tribute to the "eloquence and wisdom" of a politician who has sat in the Commons for 34 years and was one of only three people to serve in the Cabinet throughout the Labour administrations of 1997-2010. He appeared to hint at the possibility of a seat in the House of Lords for Mr Straw, who he said "will continue to serve our country in many different ways".
And Mr Straw made clear his support for Mr Miliband, saying he had "the ability, the determination and the character to take this country to a better and much fairer place than under this Government".
He promised to "devote all my energies" to putting Mr Miliband into 10 Downing Street and said he had "no doubt" that Labour can win under his leadership in 2015.
Blackburn is a rock-solid Labour safe seat which the party has held since its creation in 1955 and which delivered Mr Straw a comfortable majority of 9,856 in 2010. His departure will leave a tempting vacancy for would-be Labour candidates.
Mr Straw told constituency activists that he had made the decision to stand down after a great deal of thought and consultation with friends and family, including wife Alice.
"Labour is part of my soul, and so is this town," he told them.
"My love affair with this town is not going to end on May 7 2015, nor is my connection with it.
"But there were three issues I had to face. First, that I couldn't go on forever as the town's MP. Second, that whether I stood down in 2015, or in 2020, or whenever, it would be a terrible wrench. Third, that whilst I am as certain as anyone can be that I'd have the energy to continue at the pace necessary for three or four years, I couldn't guarantee that I could keep going at that pace right into my mid-70s.
"To take that risk would be profoundly unfair, on the electors of Blackburn, on this party, and on Alice and my family.
"Luck does play a significant part in anyone's fortunes, and, as I have said, I have been very lucky. So, to put this another way, I did not want to push my luck, to tempt providence."
Mr Straw said Mr Miliband had got the upper hand over David Cameron since announcing Labour's energy price freeze promise at his party conference last month.
"It's always wise to be careful what we wish for," said the former cabinet minister. " I bet Mr Cameron now regrets all those demands, those taunts, he made of Ed for more details of our policy. He got his answers in Ed's brilliant speech to our party's conference. With that speech Ed changed the political weather. Just two days ago, at Prime Minister's Questions, we saw Mr Cameron struggling hopelessly to say what he would do about energy prices."
Mr Straw said he would never take electoral victory for granted, but added: "I am in no doubt that under Ed Miliband we can win the general election in 2015, with Ed as prime minister, and a Labour government committed to a fairer, and therefore more successful economy and society.
"I will not be a candidate at that election. But I promise you that I will be devoting all my energies to help put Ed Miliband in Downing Street, to win in Blackburn and across the country."
Mr Miliband said: "Jack Straw will be greatly missed from the House of Commons.
"On behalf of the Labour Party, I want to thank him for his nearly 35 years service as an MP, his achievements in government and his eloquence and wisdom.
"He can be rightly proud of his role as Home Secretary, where he oversaw a fall in crime, and ordered and implemented the Macpherson report which fundamentally changed attitudes to racism and policing. He served with distinction as Foreign Secretary during the difficult times after 9/11 and played a significant role in the last Labour government's achievements as leader of the House of Commons and justice secretary.
"He can also be rightly proud of his contribution to Labour's victory in 1997 and was one of only three people to have served in the Cabinet continuously during Labour's 13 years in government.
"He has been a great friend and loyal supporter to me during my time as leader. It is a measure of the man that I know the same would have been said by the six predecessors of mine under whom he served. He is Labour through and through, and always displayed this in his words and deeds.
"He will be sorely missed but I know he will continue to serve our country in many different ways."
Mr Straw's son Will said in a message on Twitter: "I'm immensely proud of my Dad as he announces he'll be stepping down at the next election after 36 years as Blackburn's MP."
Will Straw has been adopted as Labour's prospective parliamentary candidate in the 2015 election for the Lancashire seat of Rossendale and Darwen, which neighbours Blackburn.
Shadow justice secretary Sadiq Khan said on Twitter: "Always loved working with Jack,a good friend,who remembers like it was yesterday when Moses came down the mountain..."
Tony Blair said: "Jack Straw is a true Labour giant. I was lucky enough to have him in Cabinet throughout my time as prime minister, where he put his brilliant mind to work on two of the most challenging briefs: home and foreign affairs.
"Jack's contribution to law and order in Britain and this country's standing in the world is quite simply formidable. In 2015, Parliament will lose one of the most able politicians of my generation, but I have no doubt that he will be immensely successful in whatever he turns his hand to next."
Shadow foreign secretary Douglas Alexander, who served under Mr Straw in the Foreign Office, said: "Jack has made a huge contribution to the Labour Party and the country in his 34 years in Parliament. A great boss and a good friend."